Genetic analysis of a Chinese pedigree affected with Congenital dysfibrinogenemia due to variant of FGG gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the coagulation deficit and genetic basis for a Chinese pedigree affected with Congenital dysfibrinogenemia (CD).@*METHODS@#Peripheral venous blood samples of the proband and her family members (including 4 individuals from three generations) were subjected to routine blood test and assays of liver and kidney functions and viral hepatitis to exclude related diseases. Clauss method and DFg-PT method were used to determine the fibrinogen activity (Fg:C), and an immunoturbidimetric assay was used to determine the level of fibrinogen antigen (Fg:Ag). All of the exons (22 in total) and their flanking sequences of the FGA, FGB and FGG genes were amplified by PCR and directly sequenced. Variants in the coding regions of the three genes and transcriptional splicing sites were screened by using Mutation SurveyorTM software.@*RESULTS@#The Clauss method showed that Fg:C was significantly reduced in the proband and her father, whilst her mother and son were normal. With the DFg-PT method, the proband, her parents and son were all within the normal range. The Fg:C/Fg:Ag ratio of the proband and her father was lower than 0.7, whilst her mother and son were above 0.7. No significant change in the prothrombin time, activated partial thromboplastin clotting time and thrombin time was noted. Two genetic variants were detected, which included a homozygous missense variant in the FGA gene [c.991A>G (p.Thr331Ala)], which was predicted to be benign, and a heterozygous missense variant of the γ chain of the FGG gene [c.1211C>G (p.Ser404Phe)], which is located in a conserved region and unreported in the CLINVAR/HGMD/EXAC/1000G databases and literature.@*CONCLUSION@#This pedigree has conformed to the autosomal dominant inheritance of CD. The c.1211C>T (p.Ser404Phe) missense variant of the γ chain of the FGG gene probably underlay the pathogenesis of CD in this pedigree. The variant was unreported previously and named as "Fibrinogen Harbin II Ser404Phe".

Danazol en hipofibrinogenemia congénita: dos efectos paradójicos / Danazol in congenital hipofibrinogenemia: 2 paradoxical responses

Se presentan dos pacientes con hipofibrinogenemia congénita y manifestaciones de sangrado post-quirúrgico, tratados con el andrógeno atenuado, danazol, a razón de 600 mg/día. En un caso, los niveles de fibrinógeno aumentaron y el enfermo tuvo una mejoría clínica notable.En el otro caso los niveles de fibrinógeno disminuyeron, aparecieron datos de fibrinolisis y la enferma agravó sus manifestaciones de sangrado. Se discuten las posibles explicaciones a estos efectos paradójicos, señalándose el empleo cuidadoso que de este fármaco debe hacerse en pacientes con alteraciones hereditarias de los mecanismos de coagulación